Cable feed for a cable actuated bicycle component

ABSTRACT

A cable feed for a cable actuated bicycle includes a housing and an actuator residing within the housing operatively associated with the cable. The cable feed consists of a mount attached to the housing having a mount orifice along a guide axis. A cylindrical ferrule having an axial bore extending between first and second ferrule ends includes a barb at the first end and a stop near the second end. The ferrule is axially inserted within the first end leading into the mount orifice with the stop halting axial insertion of the ferrule into the mount orifice. A minor elastic boot having a first end with an inwardly extending angular flange mates with the attachment barb and has an outer diameter at the first end large enough to prevent axial withdraw of the ferrule from the mount orifice.

RELATED APPLICATIONS

This application claims priority from U.S. Provisional PatentApplication Serial No. 60/195,560, filed Apr. 6, 2000, entitled“Mechanical Disc Brake Caliper”, the contents of which are incorporatedherein in their entirety.

TECHNICAL FIELD

The present invention is directed to bicycle components, and moreparticularly to a cable feed for a cable actuated bicycle component suchas a ball bearing mechanical disc brake caliper.

BACKGROUND ART

Bicycles commonly employ a number of cable actuated components includingderailleurs and brakes. One specific example of a cable actuatedcomponent that is being used more and more is a cable actuatedmechanical disc brake caliper, including ball bearing mechanical discbrakes. Ball bearing mechanical disc brake calipers typically consist ofa caliper housing containing a pair of brake pads positioned on oppositesides of a disc operatively associated therewith. An actuator is locatedwithin the housing to advance at least one of the brake pads intocontact with the disc. Typically the cable must be fed to the actuatoralong a select guide axis. Typically a bicycle cable within aconventional cable housing is connected to the caliper housing to directthe cable along the cable feed axis. It is desirable to limit theopportunity for grit and moisture to work their way within the cablehousing so as to prolong the life of the cable and to insure smoothoperation of the cable within the housing. Prior art cable actuatedcomponents, including bicycle brake calipers, have not adequatelyprovided a structure for minimizing this avenue for contamination. Oneproblem is that typically cable actuated component housings such as adisc brake caliper housing are a cast piece and providing a suitablestructure for attaching a cable wiper seal is difficult.

The present invention is directed to overcoming one or more of theproblems discussed above.

SUMMARY OF THE INVENTION

A first aspect of the present invention is a cable feed for a cableactuated bicycle component such as a cable actuated ball bearingmechanical disc brake caliper. The bicycle component includes a housingand an actuator residing within the housing operatively associated witha cable extending along a guide axis. The cable feed consists of a mountattached to the housing having a mount orifice along the guide axis. Acylindrical ferrule has an axial bore extending between first and secondferrule ends. The ferrule includes a barb at the first end and a stopnear the second end with a body having an outer diameter sized to beaxially received in the mount orifice between the first and second ends.The ferrule is axially inserted with the first end leading into themount orifice with the stop halting axial insertion of the ferrule intothe mount orifice. A minor elastic boot has a first end with an inwardlyextending annular flange which mates with the attachment barb. Theelastomeric boot has an outer diameter at the first end large enough toprevent axial withdraw of the ferrule from the mount orifice. Thecylindrical ferrule may further include an inwardly extending annularflange near the first end defining a cable guide orifice. Thecylindrical ferrule may also include an inner diameter between thesecond end and the annular flange sized to receive the cable housingwith an end of the cable housing abutting the inwardly extending annularflange. The elastic boot may further include a second end having a holesized to form a wipe seal with the cable received therein. Thecylindrical ferrule preferably includes a major retention barb at itssecond end and a major elastomeric boot having an inwardly extendingannular flange at a first end mating with the major retention barb and asecond end having an inner diameter sized to form a seal with an outerdiameter of a cable housing received therein.

A second aspect of the present invention is a method of making a cablefeed for a cable actuated component such as a mechanically actuated ballbearing mechanical disc brake caliper. The bicycle component includes ahousing and an actuator residing therein operatively associated with acable extending along a guide axis. The method includes providing amount attached to the housing with a mount orifice aligned along theguide axis. A cylindrical ferrule is provided, the cylindrical ferrulehaving a bore extending between first and second ferrule ends and theferrule including a first end having an outer diameter less than aninner diameter of the mount orifice and a stop near the second endhaving an outer diameter greater than the inner diameter of the mountorifice. The first end of the cylindrical end is inserted into the mountorifice with the stop abutting the mount. A boot is affixed to the firstend of the ferrule with the boot having an outer diameter sized toprevent withdraw of the cylindrical ferrule from the mount orifice.

The cable feed for a cable actuated bicycle component of the presentinvention can be readily applied to a cast component housing and enablesexpedient inclusion of wipes and seals on the cable feed for protectingthe cable operatively associated with the cable actuated component.These advantages can be provided while still enabling inexpensive andefficient casting of the component housing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view showing the ball bearing mechanical discbrake caliper of the present invention mounted to a fork of a bicycle inoperative engagement with a brake disc;

FIG. 2 is the ball bearing mechanical disc brake caliper of FIG. 1including an adapter for mounting to a frame with different mounts;

FIG. 3A is a front elevation view of the ball bearing mechanical discbrake caliper of FIG. 1 including a floating cable stop;

FIG. 3B is identical to FIG. 3A except it further includes an alternateembodiment of the floating cable stop;

FIG. 3C is a cross-section of the floating cable stop taken along line3C—3C of FIG. 3A;

FIG. 4A is an exploded perspective view of the ball bearing mechanicaldisc brake caliper of FIG. 1;

FIG. 4B is an exploded perspective view from a perspective rotated 180°from that of FIG. 4A;

FIG. 4C is a bottom perspective view of a clamp plate in accordance withthe present invention;

FIG. 5 is a cross-section of the ball bearing mechanical disc brakecaliper taken along line 5—5 of FIG. 3A with the brake pads retracted;

FIG. 6 is the same as FIG. 5 only with the brake pads extended using thepad wear compensation apparatus;

FIG. 7 is the same as FIG. 5 only it illustrates the brake pads advancedby the drive mechanism into contact with a disc;

FIG. 8 is a cross-section of the ball bearing mechanical disc brakecaliper taken along line 8—8 of FIG. 3A;

FIG. 9 is a cross-section of the ball bearing mechanical disc brakecaliper taken along line 9—9 of FIG. 8;

FIG. 10 is a right side view of the ball bearing mechanical disc brakecaliper with the lever arm in an at rest position;

FIG. 11 is a right side elevation view of the ball bearing mechanicaldisc brake caliper with the lever arm actuated to the braking position;

FIG. 12 is a cross-section of the cable feed taken along line 12—12 ofFIG. 10;

FIG. 13 is a front exploded view of the cable feed;

FIG. 14 is an exploded view of the outer indexing knob assembly;

FIG. 15 is an exploded view of the inner indexing knob assembly;

FIG. 16A is a perspective view of the ball bearing mechanical disc brakecaliper with a portion of the housing cut away to reveal the padreceiving cavity;

FIG. 16B is a sectional view of the ball bearing mechanical disc brakecaliper taken along line 16B—16B of FIG. 10;

FIGS. 17A-C are alternate embodiments of the backing plates of the brakepad assemblies;

FIG. 18 is identical to FIG. 16, only showing the pad assembly installedwith the pad assembly recess;

FIG. 19 is a perspective view of the outer knob;

FIG. 20 is a perspective view of the outer knob from a perspectiverotated 180° from that of FIG. 19;

FIG. 21 is a perspective view of the inner knob;

FIG. 22 is a perspective view of the inner knob taken from a perspectiverotated 180° from that of FIG. 21;

FIG. 23 is a front view of the lever arm illustrating the progressive,eccentric shape of the cable guide surface;

FIG. 24 is a front view of the lever arm illustrating the constant,concentric shape of the cable guide surface;

FIG. 25 is a perspective view of a ball retainer;

FIG. 26 is a sectional view of a ball retainer taken along line 26—26 ofFIG. 25 with a ball engaged therein;

FIG. 27 is a perspective view of an alternate embodiment of a ballretainer;

FIG. 28 is a sectional view taken along line 28—28 of FIG. 27 with aball engaged by the retainer; and

FIG. 29 is a plan view of an alternate embodiment of ramped grooves in afixed cam.

DETAILED DESCRIPTION OF THE INVENTION

A cable actuated ball bearing mechanical disc brake caliper 10 inaccordance with the present invention is shown in FIG. 1 mounted to aframe or, more particularly, a front fork 12 of a bicycle in operativeengagement with a disc 14. As shown in FIGS. 1-3, the caliper 10 ismounted to a front fork 12 for use with a front wheel. For use with therear wheel, the caliper is typically mounted to the seat stay, chainstay, drop out plate, after market adapter or the like. The disc 14 inturn is rigidly mounted to the hub of a wheel assembly by the bolts 16.For the sake of clarity, the bicycle wheel and hub are not shown.

The ball bearing mechanical disc brake caliper consists of a caliperhousing 18 having a pair of mounting feet 20, 22 extending therefrom forattachment to a corresponding pair of internally threaded attachmentbosses 24, 26 which extend from the front fork 12. A pair of mountingbolts 28 secure the mounting feet 20, 22 to the attachment bosses 24,26. The mounting feet preferably include elongate slots 27 (see FIG. 5)receiving the mounting bolts 28 and complimentary pairs ofconcave/convex washers 30 to provide for adjustable attachment of theball bearing mechanical disc brake caliper to a bicycle frame. Such anattachment structure is described in detail in applicant WayneLumpkin's, co-pending patent application Ser. No. 09/383,121, thedisclosure of which is hereby incorporated in its entirety herein.

As seen in FIG. 1, a lever arm 32 is pivotably attached at a first end34 to the caliper housing 18. A second end of the lever arm 36 has acable clamp 38 which secures an end of the cable 40. The cable 40 isdirected through a cable feed 42 attached to the caliper housing 18 witha cable housing 44 abutting the cable feed 42. While the operation ofthe ball bearing mechanical disc brake will be described in considerablygreater detail below, it is useful at the outset to understand that theball bearing mechanical disc brake caliper is actuated by tension beingapplied to an opposite end of the cable 40 by a cable actuator such as aconventional cable brake lever (not shown) and this tension causes thelever arm 32 to pivot about pivot axis 46 in the direction of arrow 48so that the second end of the lever arm 36 is drawn toward the cableguide 42 to advance a brake pad into contact with the disc 14 by arotary to linear linkage between the first end 34 of the lever arm 32and the brake pad.

FIG. 2 shows the ball bearing mechanical disc brake caliper 10 mountedto a front fork 12′ having internally threaded attachment bosses 24′ and26′ with an axis parallel to the axis of rotation of the disc 14. Theball bearing mechanical disc brake caliper 10′ is in all manneridentical to the ball bearing mechanical disc brake 10 described abovewith regard to FIG. 1. For simplicity, all unnecessary correspondingreference numbers have been omitted. An adapter bracket 60 is fastenedby a pair of bolts 62 to the attachment bosses 24′, 26′ and includes apair of internally threaded receptor bores 64 that enable the caliperhousing 18 to be attached to the front fork 12′ in an identical positionrelative to the disc 14 described above with respect to FIG. 1. Thus,the adapter bracket provides an equivalent mounting surface to thatprovided by the attachment bases 24, 26, as shown in FIG. 1.

FIG. 3A is a front elevation view of the ball bearing mechanical discbrake caliper 10 mounted to a bicycle frame 12 as illustrated in FIG. 1.FIG. 3 differs from FIG. 1 by the inclusion of the floating cable stop70, which will be described in greater detail below.

The ball bearing mechanical disc brake caliper 10 is shown in anexploded perspective view in FIG. 4A. FIG. 4B is identical to FIG. 4A,only the perspective is rotated 180°. First and second brake padassemblies 72, 74 consist of mirror image backing plates 76, 78 eachhaving a trailing surface 80 including a post receiving receptacle 81and a leading surface 82 to which a brake pad 84 is permanently adhered.When the ball bearing mechanical disc brake caliper is operativelyassociated with a disc 14, the disc 14 resides between the pads 84 ofthe first and second brake pad assembly 72, 74 which are held in placein part by a pad retention clip 85 in a manner which will be describedin greater detail below.

As oriented in FIG. 4A, the second brake pad assembly 74 is also knownas the back or inboard brake pad assembly. A pad wear compensator 73 forthe inboard pad assembly includes inboard pressure foot 86, which asdiscussed below, functions as an indicator. The inboard brake padassembly 74 is attached to the inboard pressure foot 86 by means of awasher-shaped magnet 88 which is adhered to a cooperatively shapedreceptacle 90 in the leading surface 92 of the inboard pressure foot 86.An axial post 94 extends through the hole in the washer-shaped magnet 88and protrudes beyond the leading surface 92 to engage the post receivingreceptacle 81 in the trailing surface of the backing plate. A trailingportion or indicator dog 96 having a rectangular cross-section extendsfrom a trailing surface of the inboard pressure foot 86 along the sameaxis of the axial post 94. The edge of the inboard pressure foot 86 isthreaded as indicated at 100 between the leading surface 92 and thetrailing surface 98. The threads 100 are sized to threadably engagecomplimentary threads 102 in the inner diameter of an inside cylinder104 of the caliper housing 18 (see FIGS. 4B and 5). This threadedengagement allows for linear advancement of the pressure foot as it isrotated. An inboard pad advancement adjustment knob 106 has knurled edge108, an axial orifice or hole 110. The axial hole is configured snugly,axially, sidably receive the indicator dog 96 of the inboard pressurefoot 86 but to prevent rotation between the pressure foot and theadjustment knob. A plurality of axially inward extending legs 112 havingradially outwardly extending barbs 114 at their distal ends. An insideindexing spring clip 116 has a plurality of radially extending legs 118sized to be received between the axially inwardly extending legs 112 ofthe inner knob 106. The inside indexing spring clip 116 further includesaxially inwardly extending bars 122 having radially outward extendingdetents 123 at their distal ends. As best seen in FIG. 5, the dog 96extends through the hole 126 in the inside indexing spring clip 116 andinto the axial hole 110 in the inner knob 106. The barbs 114 engage aninner edge of an inward extending annular flange 125 to lock the innerknob 106 against axial movement. The detents 123 in turn engage equallycircumferentially spaced indexing knurls 127 in the inner surface of theflange 125. As will be described below, the complimentary detents andindexing knurls provide a tactile indication of pad adjustment as theinboard knob 106 is rotated.

With continued reference to FIGS. 4A, 4B and 5, the caliper housing 18also includes an outboard cylinder 128 which is coaxial with the inboardcylinder 104. The bulk of the remaining components of the ball bearingmechanical disc brake caliper 10 reside within the outboard cylinder128. The outboard cylinder 128 has an annular groove 130 (see FIG. 4B)in its inner diameter sized to receive the hoop-shaped polymer dust seal132. Outboard pressure foot 134 has an identical leading surface to theleading surface 92 of the inboard pressure foot 86 and identicalreference numbers are used in FIG. 4B. Washer-shaped magnet 88′, whichis identical to washer-shaped magnet 88, is adhered within thecooperative shaped receptacle 90 of the leading surface 92 of the outerpressure foot 134. The outside or first brake pad assembly 72 isattached by the washer-shaped magnet 88′ to the leading surface of theouter pressure foot 134. The trailing surface 136 has an axiallyextending post 138 having an annular groove 140 in its side wall nearthe distal end. In the distal end is an axial cup 142. Split ring 144 issized to be received in the annular groove 140. Ball bearing 146 issized to be received in and to extend axially from the axial cup 142.

An indicator foot screw 148 has a head 149 with a leading surface 150which abuts the ball bearing 146. Behind the head 149 is a shaft 152which is threaded adjacent to the head 149 as indicated at 154. Thetrailing end of the shaft 152 has a pair of flats 156 (one shown in FIG.4A) on opposite sides. The indicator foot screw 148 is an integral partof a pad wear compensator 153 for the outboard brake pad assembly.

Drive cam 158 has an enlarged diameter base 160 having a plurality ofequally spaced curved, ramped grooves 162 in its trailing surface. Thepreferred embodiment has three ramped grooves 162 spaced at 120°. Acylindrical shaft 164 extends rearward of the enlarged diameter base 160and has an axial bore 166 which extends axially through the drive cam158. As best viewed in FIG. 5, the axial bore includes a threaded innerdiameter portion 168 which threadably engages the threaded portion 154of the foot screw 148 with the shaft 152 extending rearwardly from theaxial bore 166. Further referring to FIG. 5, an inwardly extendingflange 170 acts as a stop against a rearward portion of the head 149.The distal end of the outside cylindrical shaft 164 is threaded at 172and adjacent the treaded portion 172 is a hex portion 174. One of threeball bearings 176 resides in each ramped groove 162. The outer diameterof the enlarged diameter base 160 is sized to fit snugly within theinner diameter of the outside cylinder 128 and have a sealingrelationship with the dust seal 132 as best seen in FIGS. 5 and 7.

Fixed cam 178 has a generally cylindrical body 180 with a constant innerdiameter orifice 182. An intermediate step 184 has a spring tensionlimiting boss 186 which extends axially onto the cylindrical body 180. Aleading step 188 has an outer diameter greater than that of theintermediate step 184 and an enlarged outside diameter annular flange190 rises from the leading step 188 adjacent the intermediate step 184.A locking boss 192 extends toward the leading surface 193 collinearlywith the spring tension limiting boss 186 at a height matching that ofthe enlarged outer diameter annular flange 190. The locking boss 192 issized to key into a receiving slot 194 in the inner diameter of theoutside cylinder 128 to lock the fixed cam 178 against axial rotation(see FIG. 4A). In addition, the leading surface of the enlarged outerdiameter annular flange 190 abuts a step 196 in the inner diameter ofthe outside cylinder 128 to halt axial insertion of the fixed cam 178into the outside cylinder 128 from the opened end as viewed in FIG. 4A.The engaged relationship can best be seen in FIG. 5. The leading surface193 of the fixed cam 178 is best viewed in FIG. 4B. The leading surfacehas a plurality of equally circumferentially spaced ramped groovescorresponding to the ramped grooves of the drive cam 158. FIG. 4B showsthree ramped grooves 200 spaced at 120° which correspond to the rampedgrooves 162 of the drive cam 158, only with the ramps extendingcircumferentially in opposite directions when aligned as shown in FIGS.4A, 4B and 5-7. A ball bearing 176 resides between each ramped groovepair 162, 200 as best viewed in FIGS. 5-7. Referring to FIG. 5, withballs residing in the grooves 162, 200, the grooves and ball bearingsact as an angular contact bearing which is able to accommodate axialloads on the drive cam exerted by the lever arm 32. In addition, theramped grooves self-center the drive cam shaft 164 within the innerdiameter 182 of the fixed cam 178 with the drive cam under an axialload. This feature eliminates the need for an optional split bushing(not shown) being press fit in the inner diameter 182 of the fixed cam178. It further eliminates friction between the drive cam shaft 164 andfixed cam 178. It further reduces needs for tight tolerances between thedrive cam shaft 164 and fixed cam 178, thus eliminating the need forcostly centerless grinding of the drive cam shaft and reaming of thefixed cam bore 182. These combined advantages significantly improveperformance and minimize parts cost and assembly complexity andattendant cost.

When the fixed cam is seated within the outside cylinder 128 asdescribed above and as viewed in FIG. 5, it is locked against axialmovement by locking ring 204 which has a threaded outer diameter 206 andevenly spaced engagement slots 208 in the inner diameter 210. The innerdiameter is sized to snugly receive the intermediate step 184 of thefixed cam 178 and the engagement slots 208 allow for engagement by aspecial turning tool (not shown) so that the threaded outer diameter 206can be brought into threaded engagement with corresponding threads 212in the inner diameter of the outside cylinder 128.

A generally washer-shaped spring tension biasing plate 220 has an innerdiameter which snugly axially receives the intermediate step 184 of thefixed cam 178 and includes a spring tension limiting slot 222 whichreceives the spring tension limiting boss 186. A cut in the outerdiameter of the spring tension biasing plate forms a stop surface 224.Near the stop surface 224 is a hole 226. Return spring 228 has a pair ofaxially extending ends 230, 232. The inner diameter of the return spring228 is large enough to axially receive the fixed cam 178 and the shaft164 of the drive cam 158 as best viewed in FIG. 5. The axially extendingend 230 is received in the hole 226 of the spring tension biasing plate220 (see FIG. 5). A dust seal 234 defines an annular cover 236 for thereturn spring 228 as seen in FIGS. 4B and FIGS. 5-7. The inner diameterof the trailing orifice 238 is sized to receive and have a sealingrelationship with the outer diameter of a leading flange 240 of thelever arm 32. A hole 242 in the trailing surface of the cover 236receives the axially extending rod 232. The axially extending rod 232 inturn is received in the hole 244 near the first end 34 of the lever arm32.

A hex orifice 246 near the first end 34 of the lever 32 axially receivesthe hex portion 174 of the cylindrical shaft 164 of the drive cam 158with a hex inner diameter washer 248 therebetween to radially fix thelever arm 32 to the drive cam 158. Washer 252 abuts the trailing surface254 and is sandwiched by a larger outer diameter washer 256. The largerouter diameter washer 256 has a number of equally circumferentiallyspaced indexing knurls 258 in its outer diameter. The washers 252, 256and the lever arm 32 are axially secured to the cylindrical shaft 164 ofthe drive cam 158 by nut 260 which threadably engages the threadedportion 172 of the cylindrical shaft 164.

An outboard knob 264 has a knurled edge 266 and an orifice or axial hole268 sized and dimensioned to snugly receive the flats 156 of thetrailing end of the foot screw 148 therein, as illustrated in FIG. 5.Referring to FIG. 4B, a plurality of axially inwardly extending legs 270are equally circumferentially spaced in an inside surface of the outerknob 264. At the distal end of each axially inwardly extending leg 270is an inwardly protruding barb 272. An outside indexing spring clip 274has a plurality of axially extending bars 276 each having an inwardlyextending detent 278 near its distal end. The axially extending bars 276are sized to snugly fit between the axially inwardly extending legs 270of the outboard knob (see FIG. 4A). With the outside indexing springclip axially engaged with the outer knob 264 in the orientationillustrated in FIG. 4A, the outer knob 264 is axially advanced over thenut 260 and the inwardly protruding barbs 272 lockingly engage the outerdiameter edge of the large outer diameter washer 256 to lock the outerknob 264 against axial movement. When attached in this manner, theinwardly extending detents 278 of the outside indexing spring clipengage the indexing knurls 258 of the larger outer diameter washer 256.This can be best seen in detail with reference to FIGS. 14 and 5. Aswill be described further below, the complimentary detents and indexingknurls provide a tactile indication of pad advancement as the outboardknob 264 is rotated.

With reference to FIGS. 4A, 12 and 13, the cable feed 42 consists of amount 284 which is preferably integrally cast with the housing 18. Themount 284 includes an orifice 286 centered along a guide axis 288. Acylindrical housing stop ferrule 290 has a cylindrical main body 292having an outer diameter dimensioned to fit freely yet snugly within theorifice 286. A minor boot retention barb 294 extends axially from aleading end of the housing stop ferrule. A major boot retention barb 296extends axially from a trailing end of the housing stop ferrule 290. Anannular retention flange 298 extends radially from the main body 292adjacent to the major boot retention barb 296 and forms a stop whichhalts axial insertion of the housing stop ferrule 290 into the orifice286, as best seen in FIG. 12. Further referring to FIG. 12, the insideof the housing stop ferrule 290 has a trailing portion having an innerdiameter slightly larger than that of a standard cable housing toaxially receive the cable housing 44 therein. An annular flange 302extends inwardly to define a cable guide orifice 304. The inner diameterof the minor boot retention barb 306 is of a size between that of the attrailing inner diameter 300 and the cable guide orifice 304.

A hollow minor retention boot 310 is molded of an elastomeric materialand at its trailing edge has an inwardly extending annular flange 312configured to lockingly engage with the minor boot retention barb 294 ofthe housing stop ferrule 290. With the housing stop ferrule 290 insertedin the orifice 286 as illustrated in FIG. 12 and the minor retentionboot mounted with the inwardly extending annular flange 312 engaging theminor boot retention barb 294, the housing stop ferrule is securedagainst removal from the orifice 286. The minor retention boot has aleading nipple 314 having a leading hole 316 with an inner diameterslightly less than the outer diameter of the standard bicycle brakecable 40. In this manner, the leading nipple forms a wipe seal with thebrake cable 40 as seen in FIG. 12.

A hollow major retention boot 320 molded of an elastomeric material hasan inwardly extending annular flange 322 sized to lockingly engage withthe major boot retention barb 296 on the trailing end of the housingstop ferrule 290 as best viewed FIG. 12. The trailing end 324 has atapered inner diameter, which at the extreme trailing end is slightlysmaller than the outer diameter of the standard cable housing to form asealing relationship therewith.

With the lever arm 32 pivotably attached to the housing as illustratedin FIGS. 1-3B, 10 and 11, a curved horn 330 defining an axially flat,circumferentially curved cable guide surface 332 extends from a trailingend of the second end 36 of the lever 32. The curved horn 330 curvesabout the axis of rotation 46 of the lever arm 32. In the preferredembodiment, the curved horn is eccentric about the axis as illustratedschematically in FIG. 23 to provide for progressive increase in power asthe lever is actuated by a cable 40. Alternatively, the curved horn canbe concentric as shown in FIG. 24 or eccentric and regressive, whichthough not illustrated, would require the curved horn to have anincreasing radius as it extends toward its free end, essentially theopposite of the progressive horn illustrated in FIG. 23.

The cable clamp 38 consists of a screw 334 having a threaded shaft 336sized to threadably engage an internally threaded bore in the lever arm32 having an axis normal to the axis of rotation 46. In the preferredembodiment, a clamp plate 338 is secured between the head of the screw334 and the second end 36 of the lever arm 32. The clamp plate has a tab340 which is received in a notch 342 defined in the distal end of thelever arm 32 to fix the clamp plate against rotation. A groove 344 isformed in the underside of the clamp plate adjacent to the notch 342 toreceive the cable 40 and has a number of protrusions 345 extendingtherein to improve the grip of the cable, as illustrated in FIG. 4B.

The curved horn 330 is configured so that with the ball bearingmechanical disc brake caliper installed on a bike frame as illustratedin FIGS. 1-3B, the guide axis 288 is essentially tangent to the free endof the curved horn 330. Essentially tangent means a cable 40 does nothave a significant bend when it contacts the cable guide surface 332,but instead has a very gradual transition to the cable guide surface 332as viewed in FIG. 3. When tension is applied to the cable 40 by atension actuator such as a conventional bicycle brake lever, the leverarm 32 is drawn toward the cable feed 42. Because of thecircumferentially curved cable guide surface 332, the fixed cable clampand the fixed cable feed 42, no sharp bends are introduced to the cable40 which might fatigue the cable and lead to premature failure of thecable, which could have disastrous results for a user.

In the embodiment illustrated in FIG. 1, the conventional cable housingextends from the trailing end of the major retention boot 320. Animprovement to this conventional brake setup is to provide a floatingcable stop 70 mating with the trailing inner diameter 300 of the housingstop ferrule 290 as illustrated in FIG. 3A as part of a bicycle cableguide system. The floating cable stop 70 consists of a axially andradially rigid tube 348 made of a suitable material such as a metal likealuminum or stainless steel or an exceptionally rigid thermoplastic. Asused herein, axially and radially rigid means the tube 348 hassufficient rigidity that it will not radially buckle about itslengthwise axis upon application of tension within the normal range ofoperating tensions applied to the cable 40 which runs within the tube348. In the preferred embodiment, the tube 348 has a standardcylindrical cross-section (see FIG. 3C), although other cross-sectionsmay be useful or desired. The outer diameter is preferably essentiallythe same to that of a standard cable housing 44 so that it can fit intoa trailing end of the housing stop ferrule 290 in the same manner as thehousing 44 as illustrated in FIG. 12. This forms an axially fixedconnector for the tube 348. A connector ferrule 350 connects the tube348 to a conventional cable housing 44. This combination forms anotheraxially fixed connector for the tube 348. The conventional cable housingallows the cable to be radially deflected as may be required to attachthe cable to a brake lever. A significant advantage of the floatingcable stop 70 is that when it replaces conventional cable housings, itprovides a straight path for the cable inside with minimal or no contactwith the inner diameter of the tube. Over all but the shortest oflengths, the axially flexible cable housing will radially buckle aboutthe lengthwise axis under application of even minor tension to the cablewithin and the resultant compression to the cable housing. Eliminationof this buckling further reduces contact of the cable with the innerdiameter of the tube and serves to further minimize friction on thecable. The floating cable stop can be deployed wherever there is astraight length of cable, independent of fixed housing stops on thebicycle frame. It also provides a protective barrier for the cable, muchlike conventional cable housing, but at a lesser weight.

In a preferred embodiment illustrated in FIG. 3B, a small length ofconventional housing 352 is disposed between the tube 348 and thehousing stop ferrule 290 and is joined to the tube 348 by connectorferrule 354 to form an axially fixed connector. The transition housing352 is advantageous because it will radially flex in the event of alateral blow to the tube 348 and thereby minimize the risk of bending ofthe tube 348 which would detract somewhat from its performance and couldeven result in undesired radial buckling of the tube 348. Preferably,the transition housing 352 is of a length that will not radially buckleunder application of operating tensions to the cable 40 but will stillprovide sufficient radial flexibility to protect the tube 348.Alternatively, if required, the transition housing 352 could be longenough to bend the cable as required to properly direct the cable to thecable feed. Or, an apparatus such as the ROLLAMAJIG, manufactured toAvid, L.L.C., of Englewood, Colo., U.S. Pat. No. 5,624,334, thedisclosure of which is hereby incorporated by reference, could besubstituted for the transition housing to minimize friction where a bendis required to direct the cable.

It should be apparent to those skilled in the art that floating cablestop 70 could be deployed on any cable actuated bicycle component,including cantilevered brakes, caliper brakes, side pull caliper brakesand derailleur.

The first and second brake pad assemblies 72, 74 are made to beremovable from the caliper housing when a rotor is not operativelyassociated with the caliper housing between the brake pad assemblies.Referring to FIG. 16A, a retention structure for the first and secondbrake pad assembly 72, 74 is illustrated. The caliper housing has acavity 360 configured to receive the disc or rotor 14. The cavity 360has a mouth 362 at a leading end and includes a pair of opposingrecesses 364 (one shown in FIG. 16A). The recesses 364 are configured tonest the backing plates 76, 78 of the brake pad assemblies 72, 74 onopposite sides of the disc so that the friction pads 84 can be broughtinto and out of engagement with the disc by an actuating or driveapparatus along an advancement axis 366 in a manner that will bedescribed in greater detail below. At a leading end 368 of pad assembly72 is a retention tab 370 formed from a pair of extending posts 372, 374having oppositely extending protrusions 376. Referring to FIG. 16B,within the cavity 360 opposite the mouth 362 is a retention clip cavity378 opening into the cavity 360. Engagement flanges 380 extend fromopposite sidewalls of the retention clip cavity. Pad retention clip 85is shown in FIG. 16A installed within the retention clip cavity 378. Thepad retention clip 85 has a base 382 with a pair of extending sidewallsor legs 384, 386 with a retention detent 388 near the far end of eachleg protruding inwardly. Near the base 282 a plurality of retentionbarbs 390 extend laterally from the sidewalls or legs 384, 386. Asillustrated in FIG. 16B, these retention barbs 390 are configured tosnap fit with the engagement flanges 380 to lock the pad retention clip85 within the retention clip cavity 378.

Referring back to FIG. 16A, the pad assembly 72 is installed by graspingthe handle 392 and advancing the leading edge 368 into the mouth 362along the engagement axis 394 and aligning the retention tab 370 withthe pad retention clip 85 and further advancing the pad assembly so thatthe protrusions 370 mate within the retention detents 388. The pad canthen be slid into the recess 364 along the advancement axis 366 to seatthe pad assembly within the recess 364, as viewed in FIG. 18. Whenseated in this manner, the walls of the recess 364 secure the padassembly against movement transverse the advancement axis 366 as arotating disc is engaged. As best viewed in FIG. 5, it should beappreciated that the axial post 94 of the respective inboard or outsidepressure foot 86, 134 is received within the receptacle 81 and thetrailing surface 80 of the backing plates to thereby prevent withdraw ofthe pad assembly from the mouth 362 of the cavity 360 with the brake padseated as illustrated in FIG. 18. This connection is also the primarysupport against withdraw along the engagement axis as the pad assemblyis advanced and withdrawn by the actuation mechanism. The magnet 88 or88′ holds the backing plate in abutment with the respective pressurefoot 86, 134 to maintain engagement between the axial post 94 and thereceptacle 81. As the brake pads are advanced along the advancementaxis, the cooperating engagement flanges 380 of the pad retention clipand the protrusions 376 of the pad retention tab define a railfacilitating movement forward and backward along the advancement axis.The pad clips can be easily removed from the orifice simply by manuallyadvancing them inward along the advancement axis to bring the receptacle81 out of engagement with the axial post 94 whereupon the engagementflanges 380 can be snapped out of engagement with the protrusions 376.As shown in FIGS. 16A and 16B, the handle 392 has straight edges. Tofacilitate gripping, the handle may be modified as shown in FIGS. 17A-C.In FIG. 17A, the handle has a distal enlargement 395. In FIG. 17B, thehandle has grooves 396. In FIG. 17C, the handle has knurls or bumps 397.Other grip enhancing structures will also be apparent to those skilledin the art.

The operation of the ball bearing mechanical disc brake caliper 10 drivemechanism is best understood with reference to FIGS. 1, 5, 6, and 7.Upon actuation of the lever arm 32 by tension applied to the cable 40,the lever arm rotates about the pivot axis 46 in the direction of arrow48. This in turn causes rotation of the drive cam 158 about this sameaxis. As the drive cam 158 is rotated, the ball bearings 176 cause thedrive cam to advance within the outside cylinder 128 which in turnadvances the foot screw 148 which is threadably engaged with the drivecam. The leading surface 150 of the foot screw 148 in turn advances theball bearing 146 and the outside pressure foot 134 to urge the pad 84 ofthe outside brake pad assembly 72 into contact with the disc. Furtheradvancement will deflect the disc 14 into contact with pad 84 of theoutside brake pad assembly 74, as illustrated in FIG. 7. Upon release ofthe tension in the cable, the lever arm is biased back to its at restposition by the return spring 228 and the pads are retracted out ofcontact with the disc to reassume the position illustrated in FIG. 5.

FIG. 10 illustrates that with the lever arm 32 in an at rest position,the cable extends between the cable clamp 38 and the cable feed 42 at aslight angle. With the lever arm 32 rotated about the pivot axis in thedirection of arrow 48 so as to bring the pads into engagement with thedisc, the lever arm advances axially along the advancement axis with theouter brake pad assembly 72 so that this slight angle is eliminated, asseen in FIG. 11. Thus, it is desirable that the axially flat,circumferentially curved cable guide surface 332 be wide enough in theaxial direction to accommodate the axial movement of the lever arm 32. Athe pads wear, it may be necessary or desirable to advance the pressurefeet within the inboard and outboard cylinders to maintain the originalspacing between the pads and the disc. The present invention provides apad wear compensating apparatus that allows for such advancement (orretraction) by rotary to linear linkages between the knobs 106, 264 andthe respective pressure feet 86, 134 and associated pads.

As described above, the pad wear compensator includes inboard pressurefoot or inboard indicator 86 which is threadably engaged with thesidewall of the inside cylinder. Rotation of the inner knob 106 in aclockwise direction advances the pressure foot within the cylinder andtherefore the pad assembly along the advancement axis as illustrated inFIG. 6. As the pressure foot is advanced, the trailing end or indicatordog 96 received in the axial hole 110 of the inside knob 106 advances,to provide both a visual and tactile indication of the amount thepressure foot has advanced within the inside cylinder. In addition, theradially outwardly extending detents 124 of the inside indexing springclip 116 engage with equally circumferentially spaced knurls 126 in theinner diameter of the flange 125 to provide a tactile indication ofmovement of the knob. The knurls 126 and radially outwardly extendingdetents 124 are spaced so that each engagement between the detents andsockets indicates a uniform linear distance of advancement of the padtoward the disc. For example, in the preferred embodiment, each tactileclick equates to {fraction (1/16)} of a full rotation and {fraction(1/16)} of a millimeter of pad advancement. The inboard pad assembly isretracted by rotating the inside knob counterclockwise.

The outboard pad wear compensation apparatus 153 relies on a similarrotary to linear linkage as the inboard pad compensator 73, but it isslightly more complicated. Rotation of the outside knob 264 in aclockwise direction in turn causes rotation of the indicator foot screw148 in a clockwise direction. This rotation threadably advances theindicator foot screw 148 relative to the drive cam 158 which in turnadvances the ball bearing 146, the outside pressure foot 134 and thecorresponding first brake pad assembly 72. The outside pressure foot inits advanced position is illustrated in FIG. 6. It should be noted thatthe split washer 141 received in the annular groove 140 causes frictionbetween the outside pressure foot and the fixed cam to prevent theoutside pressure foot from simply sliding out of the outside cylinder.As with the inside knob, the outside knob also provides a tactileindication of rotation corresponding to a select linear advancement.This is provided by the inwardly extending detents 278, which engagewith the indexing knurls 258 of the larger outer diameter washer 256. Inaddition, as described above, advancement of the indicator foot screw148 and therefore the outside pressure foot 134 can be monitoredvisually and by feel by noting how far the trailing end 156 of theindicator foot screw 148 advances relative to the outer surface of theouter knob 264 within the axial hole 268. To retract the pad, theoutside knob is rotated counter-clockwise to retract the indicator footscrew 148 and the drive mechanism is actuated to squeeze the disc, whichin turn retracts the outside pad assembly 72 and the outside pressurefoot 134 by forcing them into abutment with the retracted foot screw148.

The pad wear compensating apparatus not only allows for convenientadvancement of the brake pad assemblies as the brake pads wear, but thestructure also provides a quick and convenient way to properly align thecaliper housing 18 relative to a disc 14. This can be done by looseningthe mounting bolts 28 and then advancing the pad assemblies into contactwith the disc using the inboard and outboard pad wear compensators 73,153. With the disc squeezed between the pads, the mounting structureincluding the slotted mounting feet 20, 22 and the concave and convexwashers 30 enables precise alignment of the caliper housing to maintainthe leading pad surfaces parallel to the disc. Tightening the mountingbolts 28, 30 then secures the precise alignment. For example, becausethe inner pad assembly is stationary, it is generally preferred toprovide a very small clearance between the inner pad and the disc and agreater clearance between the moveable outer pad and the disc. This setup can be achieved by starting with the pads fully withdrawn along theadvancement axis into the cavity 360 as shown in FIG. 5 and thenadvancing the inner pad assembly using the inner knob a short distancewhile advancing the pad associated with the outer knob a greaterdistance into contact with the disc. The mounting bolts are thentightened and the knobs are turned to retract the pad assemblies toprovide a desired operative gap with the disc.

While this greatly simplifies the process of properly aligning thecaliper housing and brake pads during initial set up, the padadvancement structure in combination with the caliper housing mountingsystem also provide for simplified field repair. For example, if a usercrashes and one of the attachment bosses is bent, the user can detachthe mounting bolts 28, bend the bent attachment boss back in position aswell as possible by eye-balling it and then reposition the caliperhousing with the brake pads properly aligned parallel to the disc simplyby repeating the procedure described in the preceding paragraph.

Referring to FIG. 6, in operation, as the brake pads are caused tocompress the disc therebetween, a high tensile force represented by thearrow 398 is applied to the housing in the vicinity of the inside andoutside cylinders. This can put tremendous stress on the housing, andcan even cause the housing to split apart. This problem is all the moreacute where the housing is cast from a lightweight, relatively lowtensile strength metal such as aluminum. To address this problem, theball bearing mechanical disc brake housing has a pair of threaded bores400, 402, which extend the width of the housing on opposite sides of andradially spaced from the pivot or advancement axis 46. Referring to FIG.8, a steel screw 404 threadably engages each threaded bore 400, 402 andis tightened to pre-stress or preload the caliper housing. Preferablyonly a portion of the bore opposite the screw head is threaded, with thereminder of the bore being a clearance bore. The compression force isillustrated by arrows 399. The screws are preferably tightened to applya compression force of about 1,000-1,400 lbs. This not only preventscracking and failure of the housing, it virtually eliminates any flexureof the housing that could dissipate braking power or fatigue thehousing.

The ball bearing mechanical disc brake caliper 10 also includes amechanism for adjusting the return force on the lever arm 32 applied bythe return spring 228. Referring to FIG. 9, adjustment screw 410 isthreadably received in a threaded bore 412 in the housing which breachesthe outer cylinder with the axis of the bore 412 aligned with the stopsurface 224 of the spring tension biasing plate 220. As the adjustmentscrew 410 is advanced within the treaded bore 412, the spring tensionbiasing plate 220 rotates about the cylindrical body 180 of the fixedcam 178 to increase the tension on the spring. Turning the adjustmentscrew 410 to retract it from the bore causes rotation of the springtension biasing plate 220 which decreases the tension on the spring 228.As seen in FIG. 9, the spring tension limiting slot 222 cooperates withthe spring tension limiting boss 186 of the fixed cam 178 to limitrotation of the spring tension biasing plate 220 and therefore the rangeof return force applied to the lever arm 32.

It may be useful or desirable to provide a ball spacer between the drivecam 158 and the fixed cam 178 to maintain the ball bearings 176 equallyspaced within the elongated ramped grooves 162, 200. If such a ballspacer is to be used, one embodiment of a design for such a ball spaceris illustrated in FIGS. 25 and 26. The ball spacer 420 could be made ofa simple sheet metal stamping consisting of a ring body 422 withinwardly extending radial leg pairs 424 spaced to correspond to thedesired spacing of the ball bearings. The radial legs 424 can be curledas illustrated in FIG. 25 to define a ball receiving socket 426. Thelegs 424 of each pair are circumferentially spaced so that a ballbearing 176 can be snap fit therebetween as illustrated in FIG. 26.FIGS. 27 and 28 depict another embodiment of a ball spacer molded ofplastic. Notches 427 in a ring 428 are sized to snap fit with the ballbearings 176. The ring is thick enough and the insides of the notch areslightly concave (see 429 in FIG. 27) to secure the ball bearing aboutan axis as illustrated in FIG. 28. Either ball spacer embodiment securesthe ball bearings 176 about an axis and thus ensures that the ballbearings 176 will maintain an equal radial spacing and further ensuresthat the ball bearings will be the same distance between the face of thedrive cam and the fixed cam.

The ramped groove structure of the fixed cam and drive cam illustratedin FIGS. 4A and 4B is useful for most applications, but it limits theamount the lever arm can be rotated to, at most, slightly under 120°. Analternate ramp structure is depicted in FIG. 29. As illustrated in FIG.29, the ramps 430 spiral inward as they ramp upward toward the leadingsurface 432. With such corresponding structures provided in the leadingsurface of the fixed cam and the drive cam, the ramped grooves 430 canbe much greater in length and have a much more gradual incline. Thiswill enable the associated lever arm 32 to rotate much greater than 120°and for the inboard brake pad to be advanced linearly at a slower rateas the lever arm 32 is pivoted.

The outer knob is shown in a perspective view in FIG. 19. The outer knobhas an elongate slot 440 corresponding to each axially inwardlyextending leg 270. Referring to FIG. 20, each elongate slot 440 overliesa corresponding barb 272. The holes 440 are formed during molding of theouter knob 264 by a mandrel which occupies the space that defines thehole 440, with the distal end of the mandrel contributing to the formingof the undercut of the barb. In this manner, the undercuts areintroduced to the knob while still enabling the knob to be injectionmolded in a single step. Referring to FIGS. 21 and 22, the inner knob106 likewise has elongate slots 442 corresponding to each inward axiallyextending leg 112. As with the outer knob described above, the slotsoverly the barbs 114 and enable formation of the undercut on the barbsby means of mandrels as described above with regard to the inner knob.

What is claimed is:
 1. A cable feed for a cable actuated bicyclecomponent, the bicycle component including a housing and an actuatorresiding therein operatively associated with a cable extending along aguide axis, the cable feed comprising: a mount attached to the housinghaving a mount orifice along the guide axis; a cylindrical ferrulehaving an axial bore extending between first and second ferrule ends,the ferrule including a minor attachment barb at the first end and amajor attachment barb having an outer diameter greater than an outerdiameter of the minor attachment barb at the second end, the ferrulebeing axially inserted with the first end leading into the mountorifice; a minor elastomeric boot having a first end with an inwardlyextending annular flange mating with the minor attachment barb; and amajor elastomeric boot having a first end with an inwardly extendingannular flange mating with the major attachment barb.
 2. The cable feedof claim 1 further comprising a stop near the second end of the ferrule,the stop being sized to stop axial insertion of the cylindrical ferruleinto the mount orifice.
 3. The cable feed of claim 2 wherein the minorelastomeric boot has an outer diameter at the first end adapted toprevent withdraw of the ferrule from the mount orifice.
 4. The cablefeed of claim 2 wherein the cylindrical ferrule further comprises aninner diameter between the second end and an inwardly extending annularflange sized to receive a cable housing therein, the inwardly extendingannular flange defining a cable guide orifice, a leading end of thecable housing abutting the inwardly extending annular flange.
 5. Thecable feed of claim 4 wherein the minor elastomeric boot furthercomprises a second end having a hole sized to form a wipe seal with acable received therein.
 6. The cable feed of claim 5 wherein the majorelastomeric boot has a second end with an inner diameter sized to form aseal with an outer diameter of a cable housing received therein.
 7. Acable feed for a cable actuated bicycle component, the bicycle componentincluding a housing and an actuator residing therein operativelyassociated with a cable extending from a cable housing, the cable feedcomprising: a mount on the housing having a mount orifice along a guideaxis for receiving the cable; a minor boot retention barb operativelyassociated with a first end of the mount; a minor elastomeric boothaving a first end configured to lockingly engage the minor bootretention barb and a second end having a hole sized to form a wipe sealwith the cable received therethrough; a major boot retention barboperatively associated with a second end of the mount; and a majorelastomeric boot having a first end configured to lockingly engage themajor boot retention barb and a second end having an inner diametersized to form a seal with an outer diameter of the cable housingreceived therein.
 8. The cable feed of claim 7 wherein the cable,actuated bicycle component is a disc brake caliper.